All of our polystyrene and PMMA (poly(methyl methacrylate)) microspheres are solid, non-porous polymer bead products. We do not empirically evaluate physical properties of our polymer beads, but we anticipate that many of the values associated with these properties are similar to those values reported in the scientific literature for the bulk polymers. A list of material properties for bulk general purpose polystyrene and PMMA from the literature and other internet sources may be found below. Click to download pdf version.
Electrical properties
dielectric constant (ε)
polystyrene (amorphous): 2.49-2.55 at 1kHz (curve flat to 1GHz)*
PMMA: 3.6 at 50Hz, 25ºC; 3.0 at 1KHz, 25ºC; 2.6 at 1MHz, 25ºC; 2.57 at 30GHz, 25ºC; 2.59 at 138 GHz, 25ºC*
dielectric strength
polystyrene: (ASTM D 149): 19.7-22.7 MV/m; 500-575 Volts/mil; 19.7-22.7 kV/mm**
PMMA: 17.7-60 kV/mm******
electrical conductivity
polystyrene: 10-16 S/m*******
PMMA: n/a
resistivity [unit = Ohm cm]
polystyrene: 1020 - 1022;* volume resistivity (ASTM D 257): 1.0 x 1017**
PMMA: >1015*; 1014-1015******
Thermodynamic properties
coefficient of thermal expansion [unit = K-1]
polystyrene: linear: 6-8 x 10-5 (<T); volume: 1.7-2.1 x 10-4 (<T^g), 5.1-6.0 x 10-4 (>T^g)*
PMMA: linear: 7 x 10-5 (0-50ºC); volume: 2.6 x 10-4 (<T), 2.25 - 2.72 x 10-4 (<Tg), 5.6 – 5.8 x 10-4 (>Tg)*
density [unit = g/cm3]
polystyrene (amorphous): 1.04 – 1.065*
PMMA: 1.195 (0ºC); 1.190 (20ºC); 1.188 (25ºC); 1.150 (Tg)*
glass transition temperature (Tg)
polystyrene: 80-90ºC*
PMMA: 377-378 K (104-105 ºC)*
heat capacity [Cp; unit = kJ kg-1 K-1]
polystyrene: 1.185 (1.139) at 0ºC; 1.256 (1.394) at 50ºC; 1.838 (1.821) at 100ºC*
PMMA: 0.585 at -173ºC; 0.878 at -100ºC; 1.255 at 0ºC; 1.42 (1.47) at 25ºC; 1.72 (2.02) at 100ºC; 2.05 (2.76) at 120ºC; 2.38 (3.35) at 180ºC; 4.69 (2.35) at 240ºC; 10.55 (2.50) at 300ºC*
heat of combustion
polystyrene: -4.33 x 103 kJ mol-1*
PMMA: -26,200 kJ kg-1*
heat of fusion
polystyrene: 8.37 +/- 0.08 kJ mol-1*
PMMA: n/a
heat of polymerization
polystyrene: -69.9 - -67.4 kJ mol-1*
PMMA: -57.8 kJ mol-1*
heat of solution
polystyrene: -3.60 kJ mol-1*
PMMA: n/a
melting point (Tm)
polystyrene: 240ºC (250ºC)*
PMMA: 130ºC******
thermal conductivity [unit = W m-1 K-1]
polystyrene: 0.105 at 0ºC; 0.116 at 50ºC; 0.128 at 100ºC;* 0.144;** 0.999 BTU (in/hrft2ºF)**
PMMA: 0.193 at 0-50ºC*
Optical properties
optical dispersion (ηF - ηC)
polystyrene: 1.92 x 10-2 (λ = 486.1nm, λ = 656.3nm)*
PMMA: n/a
NMR spectrum
polystyrene: peaks [ppm] at 3.0, 3.5 (aromatic), 8.4 (CH2)*
PMMA: n/a
refractive index
polystyrene: nD = 1.59 – 1.60 (λ = 589.3nm)*; 1.617 (λ = 436.8nm), 1.606 (λ = 486.1nm), 1.592 (λ = 587.6nm), 1.587 (λ = 632.8nm), 1.582 (λ = 703nm), 1.577 (λ = 833nm), 1.576 (λ = 879nm), 1.572 (λ = 1052nm)***
PMMA: nD = 1.492 (λ = 589nm); ne = 1.494 (λ = 546nm); ng = 1.502 (λ = 436nm)*; 1.502 (λ = 436.8nm), 1.497 (λ = 486.1nm), 1.491 (λ = 587.6nm), 1.489 (λ = 632.8nm), 1.486 (λ = 703nm), 1.484 (λ = 833nm), 1.483 (λ = 879nm), 1.481 (λ = 1052nm)***
UV spectrum (in vacuo)
polystyrene: absorption bands at 260nm, 194nm, and 80nm*
PMMA: n/a
Mechanical properties
coefficient of friction
polystyrene: 0.515 (20-80ºC); 0.744 (100ºC); >2 (120ºC); 0.25 (100ºC), 2.65 (110-120ºC)*; 0.35 – 0.45*****
PMMA: 0.54*****
Compressibility [unit = MPa-1]
polystyrene: 220 x 10-6*
PMMA: 245 x 10-6 (T = 20ºC); 290 x 10-6 (T = 60ºC); 355 x 10-6 (T = 100ºC); 390 x 10-6 (T = 109.3ºC); 500 x 10-6 (T = 119.8ºC); 530 x 10-6 (T = 129.7ºC); 585 x 10-6 (T = 139.3ºC)*
compressive modulus [unit = MPa]
polystyrene: 3000 (unoriented)*
PMMA: n/a
compressive strength
polystyrene: 83 MPa, 12,000 psi, 845 kg/cm3**
PMMA: 83 - 124 MPa*****
elasticity modulus
polystyrene: n/a
PMMA: 3300 MPa (25ºC)*
hardness
polystyrene: n/a
PMMA: 0.41 GPA****
Poisson’s ratio
polystyrene: 0.325 – 0.33*
PMMA: 0.34 – 0.4****
shear modulus
polystyrene: 700-800 MPa*****
PMMA: 1700 MPa (dynamic, 25ºC, 10Hz)*
tensile strength
polystyrene: 32-60 MPa*****
PMMA: 48–76 MPa*****
Young’s modulus (tensile modulus)
polystyrene: 3200-3400 MPa (unoriented)*; 3000-3500 MPa*****
PMMA: 5.0 GPa****; 1800 – 3100 MPa*****
Chemical properties
solubility parameter (δ[J/m3]1/2 * 10-3)
polystyrene: 17.4 – 21.1*
PMMA: 17.4 – 27.2*
solubility parameter (δ[cal/cm3]1/2)
polystyrene: 8.5 – 10.3*
PMMA: 8.5 – 13.3*
REFERENCES
* “Physical Constants of Polystyrene” and “Physical Constants of Poly(methyl methacrylate) and “Solubility Parameter Values” in Polymer Handbook, 2nd Ed. Eds. Brandrup, J.; Immergut, E.H.; Grulke, E.A., 2nd Edition, New York, NY: John Wiley, 1975.
** Dow’s Stryon Asia Limited Design Guide
*** Sultanova N, Kasarova S, Nikolov I. (2009) Dispersion Properties of Optical Polymers. Acta Physica Polonica A.;116(4):585-7.
**** Bhushan B, Burton Z. (2005) Adhesion and friction properties of polymers in microfluidic devices. Nanotechnology.;16:467-78.
***** IDEMAT Materials Selection Guide (2003)
****** CAE DS – Injection Moulding Materials, Polymethacrylates; Poly (methyl methacrylate) (PMMA); Technical University of Gabrovo – Milena Koleva
******* CE Carraher Jr. Carraher’s Polymer Chemistry, 8th Ed. Boca Raton, FL: CRC Press, 2010.